Improvement in methods and apparatus for molding match-plates



UNITED STATES PATENT OFFICE.

JOHN R. DAVIES, OF RAOINE, WISCONSIN.

Specification forming part of Letters Patent No. 117,391, dated July 25,1871.

To all whom it may concern:

Beit known that I, JOHN R. DAVIES, of Racin e, in the county of Racineand State of Wisconsin, have invented certain new and usefulImprovements in Molders Flasks; and I do hereby declare the following tobe a full, clear, and exact description thereof, which will enableothers skilled in the art to which my invention appertains to make anduse the same, reference being had to the accompanying drawing formingpart of this specification, in which Figure 1, plate 1, is a plan or topview of my invention as used when molding the permanent plate upon whichthe patterns-are matched. Fig. 2, plate 1, is a vertical diagonalsection of the same on line a: w, showing the manner of drawing thepatterns from the mold. Fig. 3, plate 2, is a top view of the navel forlower portion of the flask. Fig. 4, plate 2, is'a vertical transversesection of the same withi the cope or upper division attached, showing}the manner of constructing the same into the ordinary flask; and Fig. 5,plate 2, is a plan of the ordinary flask with a portion of myimprovement attached.

Similar letters of reference indicate corresponding parts in each of theseveral figures of the drawing.

My invention has for its object to improve the means for molding andcasting by what are term ed match-plates, and to this end it consists,in general terms, in the process for'matching patterns for moldingpermanent match-plates, as will be hereinafter more fully described. Myinvention also consists in a modification of the invention patented tome the 10th day of March, A. D. 1863, in order to adapt it to myimproved process.

In the drawing, A represents the flask, composed of two parts in theusual manner B, the match-board; and O, a frame secured to said board,near its outer edges, and of sufficient depth to receive the pattern orpatterns to be matched. B is the cover, secured to the upper side of theframe 0 by means of screw-bolts or other devices that will admit of itsready removal. D D are posts or uprights affixed to the four corners ofthe match-board and provided with longitudinal slots to receive guidesE, secured to the outer ends of the frame F. This frame F is formed oftwo strips of wood fastened together at right angles to each other, andextends diagonally across the match-board from post to post, to which itis attached by pins or keys (I, as shown. G G are posts attached to thecenter of the frame F and extending downward nearly to the cover B H isa vertical screw-threaded shaft, having its bearings in the center ofthe frame F, and carrying upon its lower end the cross-head I, soarranged as to move up and down by the rotation of said shaft. J aretilting-levers hinged to the outer ends of the cross-head and pivoted ator I near their centers to supports 6 depending from the under side -ofthe frame F. To the outer ends of these levers are jointed the pins L,which pass downward through openin gs in the corners of the match-boardB and rest upon the lugs M secured to the corners of the flask A, asshown. The arrangement of theseparts is such that, when the screw-shaftis rotated, the action of the le-- vers raises the match-board to drawthe pattern from the sand, as will be presently described. To the innersides of the flask A, at or near the center longitudinally, are securedlugs N N, having vertical V-shaped grooves, which receive guidepins 0 ofa corresponding shape. These pins are held in position by means ofclasps P, and extend upward through V-shaped openings cut in thematch-board B outside the frame 0, whereby said board is secured firmlyin place during the tamping of the sand to form the mold. The clasps Pextend outward through the sides of the flask, and are provided withsuitable nuts and washers to admit of their easy adjustment, the objectof which is to allow said pins 0 to be moved inward toward the center ofthe flasks by the contraction of the iron and thus retain a trueposition when the permanent match-plate is being cast. 1%, Fig. 5,represents a movable lining or inner flask, that is shaped approximatingto the shape of the flask A, and so arranged as to be readily removed.The object of this arrangement is to retain the mold in position andallow the outer. flask to be removed, thus saving great expense, as oneskeleton flask will form any number of molds.

The operation of matching the pattern or patterns preparatory to beingmolded is as follows: The match-board and frame G are placed upon aquantity of sand, either within the flask or other suitable receptacle,and the cover B removed. The pattern is then placed within the frame 0,extending below the same into the sand to the draught or parting-line.The space within the frame 0, around the pattern and even with the lowerface of the match-board, is now filled with prepared plaster of Paris orequivalent material, the cover B replaced upon the frame, and the wholelifted off the sand and inverted. By this operation the match-board andits frame contain a pattern bedded to the partingline in preparedplaster of Paris or equivalent.

It will be understood that the sand in this connection is used simply tosupport and protect the pattern while being molded in the plaster, anddoes not contain any portion of the mold which is used in the finalcasting.

The pattern is now drawn from the plaster, and a second match-boardsecured to the first in the manner usual in molding with the ordinaryflask, being held in place by the guide-pins 0 entering the lowermatchboard. The cover 13 of this second board is removed, and the entirespace withiirthe frame (J, together with the mold in the lowermatch-board from which the pattern has just been drawn, filled withplaster of Paris. The cover is then replaced and the match-boardsseparated in the usual manner of parting the common flask. By thissecond operation the second match-board contains a perfect negative ofthe mold in the first match-board. The pattern is then secured in themold first made and the match boards are complete. I have now onematch-board containii'ig a negative corresponding to one part of thepattern, and another match board in which the other projecting part ofthe pattern is formed by the pattern itself. These two boards I term thetemporary plates, from which the molds in the sand are formed,preparatory to casting, in the following manner: The temporary match-plate containing the projecting pattern is inverted to bring such patternuppermost, and the lower portion of the flask A laid upon and over it.The flask is then filled with sand which is properly tamped, and thewhole turned upside down to bring the temporary plate uppermost. Theplate, together with the pattern, is then drawn from the sand by theaction of the shaft H and levers J, and thus one-half of the mold isobtained. The upper portion of the flask A is then placed upon andsecured to the second temporary plate containing the plaster negative,and filled and tamped in like manner. The same are then turned up sidedown, the temporary plate drawn from the sand in the manner justdescribed, and thus the second half of the mold is obtained. he twoparts of the flask are then clamped together in the usual manner and themold is ready for pouring. To prevent the sand from falling through theflask around the temporary plate I provide a board corresponding to theexterior size of the flask, upon which the latter rests. The center ofthis board is removed to permit the passage through it of the frame 0 ofthe temporary plate; and when the latter is inverted to support theflask the uncut portion of the board bears against the bottom of theflask and the match-plate B, completely filling the space between theinner sides of the flask and such match-plate.

It will be readily understood that the V-shaped pins 0 also serve asguides for drawing the temporary plates and patterns from the sand.

If the patterns are designed for constant use, I prefer, as moreeconomical, to cast from the temporary plates what I denominatepermanent plates, which are metal plates having the patterns cast onthem. To accomplish this the temporary plates with their patterns aremolded in the sand contained in the flasks, and drawn by the drawingdevice, as previously described for molding the patterns.

It will, of course, be understood that the plates, as well as theirrespective portions of the pattern, are to be molded and cast, insteadof the pattern only, as when the temporary plates are employed.

In casting the permanent plates the V-shaped pins 0 in the flask formthe guide-holes in one of such plates, and must be coated with oil orother suitable substance to prevent the molten metal from adhering tothem. The V-shaped pins in the other plate are cast by fitting the pins0 of the corresponding temporary plate, when such plate is molded,within the seat of the pins 0, the latter being previously removed fromthe flask. WVhen the metal is poured into the flasks in casting thepermanent plates the nuts upon the clasps P are loosened and the claspspushed inward to permit the pins 0 or O to be moved toward the center ofthe flask by the contraction of the casting.

Instead of casting two plates with part of a pattern on each, one platemaybe cast with half a pattern on each side, so that one plate onlywould be needed for a full match; but I prefer to cast them in pairs, asdescribed.

The lugs M in the corners of the flasks are so arranged that when thepermanent plate is cast it extends between the two sets, and istherefore prevented from springing and warping while cooling.

My invention is of special advantage in molding small patterns, as anumber may be molded at the same time.

Having thus described my invention, what I claim as new is 1. Theprocess herein described for matching patterns for molding permanentmatch-plates, consisting, essentially, of the following steps: first,one part of the pattern is molded in plaster and removed therefrom 5secondly, a plaster cast of that mold or impression is taken,

which forms a temporary match-plate for the said part of the pattern 3thirdly, the pattern is returned to the plaster mold, and with it formsjustment substantially as described, for the purthe temporarymatch-plate for the other partof pose specified. the pattern, from whichtemporary match-plates 4. The combination of the keys cl, posts D,permanent match-plates may be molded, substanguides E, and frame F,substantially as described, tially as described. for the purposespecified.

2. The combination of the match-plate B, frame JOHN R. DAVIES. G, andremovable cover B substantially as de Witnesses: scribed, for thepurpose specified. G. H. FROST,

3. The pins 0 and clasps P, adapted for ad- E. A. ELLSWORTH.

